An intact human penis is covered by a single continuous sheath or skin system which is partly folded at different times. The folded portion of the skin system is called the foreskin or prepuce. Historically, the foreskin has been delineated as a separate anatomical structure; however, this is not correct. The foreskin is not a separate anatomical structure from the rest of the skin of the penis but rather it is the portion of the continuous skin system which happens to be folded over the glans at any given time.
Circumcision is the surgical procedure by which the foreskin is removed. Many cultures perform circumcision on infant males soon after birth; however, the procedure is also sometimes performed on adult males. Male circumcision is performed for a variety of reasons; religious, health, aesthetic, tradition, etc. Recent studies have brought into question some of the justifications for circumcision inasmuch as circumcision removes a complex, pentilaminar functional structure that contains nearly all fine touch neuroceptors of the penis and can reduce sensitivity of the glans penis to fine touch and vibration. Van Howe, Nat. Clin. Pract. Urol. 6(2):74-75 (2009).